Case reports suggest a familial element in the etiology of childhood brain tumors, but no systematic family studies have been conducted. This genetic epidemiologic family study proposes to collect current health histories on a cohort of 193 childhood brain tumor patients and their family members. We will determine age-specific risks of cancer of all sites and of specific sites in first degree relatives. Segregation analysis will be applied to the brain tumor pedigrees extended according to a sequential sampling rule to include selected second degree relatives under a generalized mixed model to determine a) the extent to which cancer aggregates among proband relatives; b) the frequency of brain tumor involvement in known or potentially hereditary syndromes; c) parameter estimates for the model(s) which characterizes the familial contribution of cancer in "affected" families. Findings of this study may be used to define risks to enable genetic counseling, future linkage study and to identify specific kindreds in which specific cancer-predisposing genes may be segregating.